Driftwood Sub-Zero Service · Bainbridge Island

Older-Unit Care · Seasonal houses

Musty Smell in a Unit That Sat Closed: Clearing It for Good

A Sub-Zero switched off with its doors shut in a damp island house holds its moisture, and the smell that greets you in spring comes from it.

Written by
Bjorn Aaltonen
Trade
Refrigeration technician, 15 yrs
Holds
EPA 608 certified
Dated
Hands working a new gasket into the frame of a glass-door refrigerator, the old gasket coiled on a quilted pad with two screwdrivers
Where defrost water goes: evaporator, trough, drain tube, drain pan Side section of a refrigerator. Frost melts off the evaporator during a defrost, drips into a trough, runs down a drain tube and collects in a drain pan in the machine compartment, where it evaporates. Standing water or debris in the trough, tube or pan is a common source of a musty smell. evaporator: frost melts off it in a defrost trough: catches the meltwater drain tube: runs it down drain pan: the water evaporates here (Classic built-ins: behind the kickplate) standing water or debris anywhere on this route = a musty smell
Defrost water leaves by one route. Anything that stands on it starts to smell.

Where the smell has been living

A musty smell in a unit that stood closed rarely comes from the air itself. It comes from the places that held water while the cabinet was dark and shut: the folds of the door gaskets, the shelves and their supports, and the defrost drain, where water runs from the evaporator into a trough, down a tube and into a pan underneath. The drawing above follows that path. Sub-Zero’s own list of odour causes includes standing water or foreign matter in the drain pan, clogged drain tubes, a cracked or torn door seal and an extended loss of power, and a unit switched off for a winter has had the last of those for months.

Cleaning it out properly

For a stubborn odour, Sub-Zero’s advice is to clean the whole interior, drain pan, tubes, gaskets and every crevice, with warm water, dish detergent and a capful of bleach. That mix is its method for odours specifically; for everyday interior cleaning the Classic guide asks for mild soap, water and baking soda, and rules out vinegar, rubbing alcohol and other alcohol-based cleaners. Rinse, dry every fold, and then, if you can, leave the doors blocked open with a fan running for several days, which Sub-Zero also suggests. On a Classic with air purification, its guide says to replace the cartridge if there is an odour inside.

When cleaning is not enough

If the smell survives all of that, it is usually somewhere an owner cannot reach. Sub-Zero describes taking the unit apart and cleaning the evaporator for the worst cases, and that is panel work for a technician, not for a Saturday afternoon.

What you can check yourself

  • Hold each gasket fold open with a finger and look along its full length. Dark specks in a fold are the most common source, and the smell follows them.
  • Take the shelves and drawers out and smell them away from the cabinet. If the odour goes with them, they are part of the problem, not just near it.
  • On a Classic, take the drain pan out from behind the kickplate as its guide describes, and look for standing water or sludge in it.
  • Look at the floor of the fresh-food compartment. Standing water there is on Sub-Zero's list of odour causes and often goes with a blocked drain tube.
  • Run a finger along every gasket for cracks or tears. A damaged seal is another listed cause, and no amount of cleaning mends it.

Questions we get about this

Will an open box of baking soda deal with it?
Not on its own. Anything that absorbs smell helps after the cabinet is clean, not in place of cleaning. Sub-Zero's list is crumpled newspaper, charcoal briquettes or activated charcoal in a container, or fresh coffee beans, changed daily. Baking soda belongs in the wash water. If the smell is back within days, something is still holding it, usually a fold, a shelf or the pan.
Can I clear the drain tube myself?
The drain pan on a Classic, yes; its guide explains taking it out from behind the kickplate. The tube that carries defrost water down to the pan is another matter on most units, since reaching it can mean panels off. If water stands on the compartment floor, Driftwood Appliance Service, (206) 785-2960, can find out why the tube blocked.
When does the smell mean a part has to be replaced?
When the cleaning has been done properly and the smell keeps coming back to the same place. Sub-Zero notes that shelving may need replacing after a severe odour, and a cracked or torn door gasket is on its list of causes. The manufacturer recommends that a service technician fits a new gasket, so that part of the job is ours rather than the owner's.

When the check turns something up

Put the unit on the next island run

Book a slot with the model number and what you found, or ring and talk it through first — plenty of these calls end with a check you can do yourself.

Call (206) 785-2960
Ringing
(206) 785-2960 is picked up 24/7
Island days
Out on calls 8:00 am – 8:00 pm, seven days, round every district
First visit
$89 for the trip and the diagnosis — deducted once you say yes to the repair
Districts
Winslow · Rolling Bay · Lynwood Center · Port Madison
Multimeter probe reaching into the open service bay beneath a stainless undercounter drawer unit in a wood kitchen

Online booking

Take a slot on the island run

  1. Choose a day and a time of day that works for the house.
  2. Add the model number from the unit's rating plate and a sentence on what the unit is doing.
  3. We ring back with an arrival window that fits the sailings.
Book online

Prefer to describe it out loud first? Ring (206) 785-2960 — a good description on the phone is half of an island diagnosis.

What the $89 buys: the crossing, readings taken over a cycle, and a diagnosis you can act on. Say yes to the repair and that $89 is taken off its price; the price itself is written down for you before a panel comes off.